Tension load transfer device

ABSTRACT

A tension load transfer device having a base and a transfer member connected by two webs, all of which are connected to a flange. The flange comprises a bolt hole pattern for connecting the load transfer device to a vertical support of a structure. The base comprises an anchor hole for receiving a lower tie member, and the transfer member comprises a plurality of receiving holes for receiving the respective lower ends of a plurality of upper tie members.

CROSS-REFERENCE TO RELATED APPLICATION

Pursuant to 35 U.S.C. § 119(e), this application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/788,394, filed on Jan. 4, 2019, the entire contents of which are incorporated herein by this reference.

BACKGROUND (1) Field of Endeavor

The present invention relates generally to the field of multi-story tension tie systems, and more particularly, to coupling devices between tension ties in multi-story construction.

(2) Description of Related Art

Multi-story buildings are often subjected to uplift forces caused by seismic or wind loads, or some other type of loading. Absent proper structural support, the building can experience uplift loads that significantly exceed the capacity of typical construction materials. To prevent failure of such materials, and therefore failure of the building, post-tensioning systems are sometimes used to anchor certain structural members to the foundation. In some construction configurations it is desirable to place multiple stories under a compression load, and the post-tensioning strands, or tie members, must span across multiple stories to deliver these loads. Instillation of such tie members in multi-story construction can be cumbersome and awkward because the tie members must be placed and jacked during the construction sequence.

Another complication is that in multi-story tension systems, the effects of long-term shrinkage can reduce the effectiveness of the tension system. The shrinkage effects reduce the amount of tension in the tension tie members, and the tie system must account for these effects to deliver long-term viability.

The present tension transfer device seeks to overcome these problems by providing a mechanism capable of transferring, or transitioning, the tension loads across the interface(s) between the stories of multi-story construction.

SUMMARY OF THE PREFERRED EMBODIMENTS

The present tension load transfer device has a base and a transfer member connected by two webs, all of which are connected to a flange. The flange comprises a bolt hole pattern for connecting the load transfer device to a vertical support of a structure. The base comprises an anchor hole for receiving a lower tie member, and the transfer member comprises a plurality of receiving holes for receiving the respective lower ends of a plurality of upper tie members.

The tension load transfer devices may be used to transfer load between a plurality of lower tie members that differ in number than that of the upper tie members. To accommodate this potential imbalance in configuration, in one embodiment the first and second web members further comprise a transition region, such as a chamfer, fillet, taper, or other similar transition feature.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial elevation view showing one embodiment of the tension transfer device installed in multi-story construction.

FIG. 2 is a partial elevation view showing one embodiment of the tension transfer device installed in multi-story construction.

FIG. 3 is an isometric view of one embodiment of the tension transfer device placed for installation in relation to a typical horizontal member and a typical vertical support.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the drawings, the tension load transfer device will now be described with regard for the best mode and the preferred embodiment. In general, the device transfers certain tension loads between stories of multi-story construction, where the tension loads are delivered by tension tie members. The embodiments disclosed herein are meant for illustration and not limitation of the invention. An ordinary practitioner will appreciate that it is possible to create variations of the following embodiments without undue experimentation.

Referring to FIGS. 1-2, in one embodiment the tension load transfer device 10 is installed at an interface between the tension tie members of adjacent stories of a multi-story building. The tension tie member could be a cable, wire rope, tensioning strand, tension bar (threaded or unthreaded), or some other member configured for subjecting a story of a building to a compression load. The tension tie members are often a component of a post-tensioning system for resisting uplift on the building.

For example, referring to FIG. 1, first and second stories 11, 12 of a building may be separated by a horizontal member 14. First and upper tie members 15, 16 are configured for applying compression loads to first and second stories 11, 12, respectively. In most applications, the tension load transfer device 10 is installed above a horizontal member 14 to transfer the forces between first and upper tie members 15, 16, as described in more detail below. In this exemplary configuration, lower tie member 15 is anchored into the building foundation 17, passed through the horizontal member 14, and anchored within the tension load transfer device 10. In other embodiments, the lower tie member 15 is anchored at its lower end near the bottom of a horizontal member 14 of a lower story in the building. In either of these embodiments, the lower tie member 15 is tensioned to the load necessary to place the first story 11 (or a lower story) in the desired amount of compression to resist certain uplift loads. The upper tie member 16 is then attached to the tension load transfer device 10 (as described below), and anchored at its top end to a horizontal member 14 near the top of the second story 12.

Referring to FIG. 3, to assist in describing the tension load transfer device 10, coordinate system 18 has a vertical axis 18 a, a horizontal axis 18 b, and a transverse axis 18 c. In general, the tension load transfer device 10 is installed on the horizontal member 14 and connected to a vertical support 19, which is oriented in substantial alignment with the vertical axis 18 a.

The tension load transfer device 10 generally comprises a base 20, first and second webs 21, 22, a flange 23, and a transfer member 24. The base 20 is generally rectangular in shape (in plan view) such that placement of the base 20 on the horizontal member 14 results in a substantial alignment of these two members. The base 20 has one or more anchor holes 25 for receiving and anchoring the top end of the lower tie member 15. The base 20 is securely connected to the first and second webs 21, 22 and to the flange 23. The first and second webs 21, 22 are attached to opposite sides of the base 20 such that the base 20, first and second webs 21, 22, and flange 23 define a box-like shape.

These components are connected together by a means for a secure connection, such as by welded connections, bolted connections, or by other equivalent means. Likewise, the first and second webs 21, 22 are similarly connected to the flange 23. The webs 21, 22 are configured for transferring the loads between the lower tie member 15 and the upper tie member 16. The webs 21, 22 are connected at their respective lower ends (in relation to the vertical axis 18 a) to the base 20, and at their respective upper ends to the transfer member 24.

Optionally, the flange 23 comprises a pattern of bolt holes 26 for receiving mechanical fasteners, such as bolts, to connect the flange 23 to the vertical support 19. The number and configuration of bolt holes 26 is selected to develop the desired force between the tension load transfer device 10 and the vertical support 19. Alternatively, the flange 23 can be attached to the vertical support 19 by welds if either both members or a connecting bracket comprise weldable material.

The transfer member 24 comprises one or more receiving holes 27 for receiving the lower end of the upper tie member 16. For example, the transfer member 24 may comprise three receiving holes 27 a, 27 b, 27 c for receiving the respective lower ends of upper tie members 16 a, 16 b, 16 c. The transfer member 24 comprises a means for transferring load from the lower tie member 15 to the upper tie member 16, the transferring means being a plate, a block, a channel, a cylindrical segment, a hexagonal segment, or any other equivalent structure for load transfer. For example, in the embodiment shown in FIG. 3, the transfer member 24 comprises a hexagonal segment oriented such that one side of the hexagon is substantially parallel to the plane of the base 20. In this embodiment, the transfer member is integrally connected to the first and second flanges 21, 22.

The embodiment shown in FIG. 2 depicts a single lower tie member 15 and three upper tie members 16 connected to the tension load transfer device 10. An other embodiments, the tension load transfer device 10 is configured to transfer load between a plurality of lower tie members 15 and one or more upper tie members 16. In other words, the number of lower tie members 15 can be more or less than the number of upper tie members 16. For example, in an embodiment of the tension load transfer device 10, the base 20 comprises a plurality of anchor holes 25, where each such anchor hole 25 is configured for receiving and anchoring the upper end of a lower tie member 15, while the transfer member 24 comprises a single receiving hole 27 that is configured for receiving and anchoring the lower end of an upper tie member 16.

Because the number of lower tie members 15 and upper tie members 16 is not necessarily equal, in one embodiment the first and second webs 21, 22 each comprise a transition region 30 to translate the tension load between the base 20 and the transfer member 24. The transition region 30 is a chamfer, fillet, taper, or equivalent structure of the first and second webs 21, 22. For example, in FIG. 3 the transition region 30 is a fillet.

The present tension load transfer device 10 has the effect of counteracting the long-term shrinkage effect of a building, and especially in multi-story construction. Thus, use of the present tension load transfer device 10 reduces, or even eliminates, the need for separate shrinkage compensation devices. Additionally, placement of the tension load transfer device 10 on the second story, as shown in FIG. 1, reduces the stress on the nails in any shear panels installed in the first story. Thus, the present tension load transfer device 10 acts to prevent shear panel failure caused by overstress nails or tearing of nail holes in proximity to the panel nails or fasteners.

The foregoing embodiments are merely representative of the tension load transfer device and not meant for limitation of the invention. For example, persons skilled in the art would readily appreciate that there are several embodiments and configurations of transfer members and first and second webs that will not substantially alter the nature of the device. Consequently, it is understood that the true scope of the invention is set forth in the claims below. 

I claim:
 1. A tension load transfer device comprising: a base having one or more anchor holes, each anchor hole configured for receiving an upper end of a lower tie member; a transfer member connected to the base by two webs, the transfer member comprising a plurality of receiving holes, each receiving hole configured for receiving a lower end of an upper tie member; and the base, the transfer member, and the webs all connected to a flange.
 2. The tension load transfer device of claim 1, wherein each web further comprises a transition region configured for transitioning a tension load between the base and the transfer member.
 3. The tension load transfer device of claim 1, wherein the transfer member further comprises a hexagonal segment.
 4. The tension load transfer device of claim 1, wherein the flange further comprises a pattern of bolt holes.
 5. The tension load transfer device of claim 2, wherein the transfer member further comprises a hexagonal segment.
 6. The tension load transfer device of claim 2, wherein the flange further comprises a pattern of bolt holes.
 7. The tension load transfer device of claim 5, wherein the flange further comprises a pattern of bolt holes.
 8. A tension load transfer system comprising: one or more upper tie members, each upper tie member having a lower end comprising an anchor attachment; one or more lower tie members, each lower tie member having an upper end comprising an anchor attachment; a base having one or more anchor holes, each anchor hole configured for receiving the upper end of a lower tie member; a transfer member connected to the base by two webs, the transfer member comprising one or more receiving holes, each receiving hole configured for receiving the lower end of an upper tie member; and the base, the transfer member, and the webs all connected to a flange.
 9. The tension load transfer system of claim 8, wherein each web further comprises a transition region configured for transitioning a tension load between the base and the transfer member.
 10. The tension load transfer system of claim 8, wherein the transfer member further comprises a hexagonal segment.
 11. The tension load transfer system of claim 8, wherein the flange further comprises a pattern of bolt holes.
 12. The tension load transfer system of claim 9, wherein the transfer member further comprises a hexagonal segment.
 13. The tension load transfer system of claim 9, wherein the flange further comprises a pattern of bolt holes.
 14. The tension load transfer system of claim 12, wherein the flange further comprises a pattern of bolt holes. 